replying to RogerN , passerby wrote:
regor wrote:

snip
I was thinking of using the 4pc controller as an amplifier box and using
LinuxCNC as the controller to provide PWM to the 4pc controller.

That 4PC controller is essentially a glorified power supply that simply
passes the signals from encoders over to the PC Servo card and receives
PWM for each motor back. There is also a serial line to the teach pendant
that sort of simply passes through. 4U controller looks the same but the
brains have been moved from the PC Servo card into the controller, so it's
an actual controller together with a power supply, in one box.

I have
used the Mesa anything I/O boards with LinuxCNC and it has encoder inputs
and PWM outputs. I don't know if the 4PC control takes pwm plus direction

or exactly what. I thought I could get the Mesa board to replace the PC
board for the ER4PC controller, I found the 62 pin high density Sub-D
connectors at Digi-Key.

I have some kind of unverified pinout for that 62-pin cable from a USC
Wiki page for the university's robotics lab that now requires a user name
for some reason. I'd be happy to share although it looks suspicious
because I cannot find directions (or polarities) identified anywhere and
motor control lines are called "Axis 1 Speed" (PWM?) - only one pin per
motor. How would it know direction then is a question. Almost all of the
other lines are taken by the encoders (there's 6 on the robot itself and 2
more for external axes like linear stage and pickup rotary table) or not
connected (or marked as +5V which is also suspect, you would think they'd
be grounded instead).





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